Apparatus for shaping sheet-metal articles



Oct. 28 Q1924.

W. W. SOMERSALL APPARATUS FOR SHAPING SHEET METAL ARTICLES 2SheeLs-Sluaei. 1

Filed Oct. 30, 92a

9 Inna 5 9 5 I'm: 10 9 I Oct. 28 1924. 1,513,565

w. w. SOMERSALL Patented Oct. 28, 1924.

UNITED STATE P AT WILLIAM WARREN SOMERSALL, OF NATICK, MASSACHUSETTS,ASSIGNOR TO NEW ENGLAND PRESSED STEEL COMPANY, OF NATICK, MASSACHUSETTS,A CORPORA- TION OF MASSACHUSETTS.

APPARATUS FOR SHAPING SHEET-METAL ARTICLES.

Application filed October 30, 1922. Serial No. 597,783.

To all whom it may concern:

Be it known that I, WILLIAM TV. SOMER- SALL, a citizen of the UnitedStates, residing at Natick, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inApparatus for Shaping Sheet-Metal. Articles, of which the following is aspecification.

This invention relates to punch and die apparatus of the character usedin the pressed metal industry. The invention will be herein disclosed asembodied in an apparatus designed especially for use in making tubularwrenches, such as spark plug wrenches, and the like, although theinvention may also be used to advantage in the manufacture of a greatvariety of hollow sheet metal articles.

As is well understood by those skilled in this art, it is the usualpractice to manufacture wrenches of the tubular type by starting with aflat metal blank. This blank is subjected to a series of cupping anddrawing operations until it is worked into an elongated cup-shaped form.Usually it is then necked; that is, a shank of reduced diameter isformed in the closed end of the blank. This neck or shank is next giventhe desired cross sectional outline, usually that of a square, and theblank is then forced through a die which gives the body the desiredpolygonal outline. This usually is either a square or an hexagonal form.These shaping and drawing operations are performed by forcing the blankthrough suitable dies while the blank is cold, or at ordinarytemperatures, and consequently it subjects the walls of the apertures inthe dies to very rough usage. These walls soon become scored, worn, ormis-shapen, and after only a very short time it is necessary to discardthe die and replace it with a new one. Often such dies last-only duringthe shaping of three hundred or four hundred pieces of work, and evenunder very favorable circumstances they Will rarely last for more thanseven thousand or eight thousand pieces. Such dies are expensive tomanufacture and when a die is worn out and must be replaced,considerable time is lostin setting and adjusting the new die. Thepercentage of imperfect pieces of work pro duced by such dies also ishigh.

With these considerations in mind, it is the chief object of thepresent'invention to improve the construction of dies of the generalcharacter above mentioned with a View to reducing their cost ofmanufacture, providing a die construction which will give substantiallygreater length of service, will reduce the percentage of defectivepieces of work produced, and will result in economies in the repair andchanging of the tools.

The nature of the invention willbe readily understood from thefollowingdescription when read in connection with the accompanying drawings, andthe novel"fe'atu'res will be particularly pointed out in the appendedclaims. Y In the drawings, Figure 1 is a plan view of a die constructedin accordance with this invention;

Fig. 2 is a vertical cross sectional view on the line 2-2, Fig. 1;

Fig. 3 is a perspective view showing certain details of the dieconstruction;

Fig. 4 is a perspective view of the die and a punch for forcing the worktherethrough;

Fig. 5 is a perspective view of a tubular wrench blank at anintermediate stage in the necking operation; I V

Fig. 6 is a perspective view of the blank after the shapingof the neckhas been completed;

Fig. 7 is a perspective View of the blank after it has been forcedthrough the die shown in Figs. 1 and 2;

Fig. 8 is a plan View of a necking die embodying the present invention;and

Fig. 9 is a cross sectional view on the line 99, Fig. 8.

Referring first to Figs. 1 to 4 inclusive,

the die there shown comprises top, bottom and intermediate platesdesignated at 2, 3 and 4, respectively. These plates are registered bymeans of dowel pins, and they are all secured together bybolts 5. j Thebottom plate 3 preferably has a central projection 6 formed thereonwhich extends into a recess or aperture in the bottom of the centralplate 4 and thus aids in holding these two plates in the. properrelationship. These I plates are all apertured centrally, the aperturesregistering with each other to form a hole that extends verticallythrough the die, and t smu of the aperture in the plate has siX notchesor recesses formed in it, as best shown at 8, Fig. 3. Positioned withineach of these recesses is a roll 9, each roll fitting snugly in itsrecess and resting on the lower plate 3.

The die shown is designed to give the hexagonal form to the body of thewrench, and the six rolls 9 are arranged, as clearly shown in Fig. 1, toform the walls of a restricted aperture having this outline. in order toprevent 'the rolls from moving forward into the aperture, the upperplate 2 hasgrooves formed therein, as indic'a'ted at 10, Fig, 2, toreceive the rolls, sufficient clearance being provided to enable therolls to rotate fr ee ly about their individual axes. It will beobserved from an inspection'of Fig. 3 that the walls of the platetwhi'ch separate the recesses 8, curved at their forward edges so thattheir faces "merge substantially with the adjacent surfaces of therolls.

, When the blank B, F 6, is forced through the by means o f the punch12, Fig.4,thebody of the blank will be reshaped and. its circularputliie will be changed to the nagonal formshown at C in Fig. 7. Thisre-shaping is effected by the punch 12 forcing the metal into contactwith therolls 9 these rolls rotating freely about their axes and beingheld in their cooperative relationship to eachother by the other partsof the die. It should be noted that the rolls are supported by theirperipheral engagement with the walls of the recesses in which they aremounted, as distinguished from being supported axles or trunnions.

to the fact that the work-shaping surfaces of the die, namely the rolls,'move with'the work as it is forcedtherethrough, the friction on the diesurfaces is greatly reduced and the power required to perform thisoperation is correspondingly reduced. 1 have found in actual practicethat a die of this construction will outlast the usual dies severaltimes. Furthermore, itgreatly reduces the percentage ofimperfect piecesof work, since the tendency to score either the work or thewalls of thedie is practically eliminated. Due to thereduced friction, a

die of this construction runs much cooler than theusual forms of dies.l/Vhen the rolls have become worn to such an extent that the d e is nolonger fit for service, it s simply necessary to replace them, and thedie is read for use a ain. Such a reolacement D i m yb ma at a triflingexpense and withu-t disturblrrg the setting or adjustment of the die.The saving thus eHected in tool repairnis a very substantial item.

in Figs, Sand 9 a slightly different construction is shown,thepartioular die there illustrated being designed especially for per-'-forming the necking operation on the blank A. This constructioncomprises top, bottom and middle plates, designated at13, 14 and 15,respectively, and it also includes a series of rolls 16. These rollsrest on the lower plate lei and they are located in notches or recessesformed in the central plate 15, as in the construction above described.Each roll, however, is provided with bevelled ends and with shorttrunnions 17. The bevelled ends prevent the rolls from moving forwardinto the aperture, as will readily be appreciated from an inspection ofFig. 8. The trunnions 17 are not subjected to any strain during theshaping of the work, the rolls being supported at this time by theirperipheral engagement with the plates 14 and 15 in the same way that therolls 9 are upported in the construction above described; but thetrunnions engage the upper plate 8 when'thework is pulled back throughthe die, and they thus hold the rolls in their proper relationship at"this time.

This construction has substantially the same advantages as that shown inFigs. 1 and 2.

While I have herein shownand described the best embodiments of myinvention which I have so far devised, it will be appreciated that theinvention is not limited to embodiment in the precise form shown,

Having thus describedmyinvention, what I desire to claim as new is:

1. A die for the coldshaping of hollow sheet metal articles, comprisinga roll for shaping one face of the work, additional die memberscooperating with said roll to support it and shape the worle saidmembers including stationary parts locate dat opposite ends of said rollhaving faces curved to substantiallymerge with thesurface of the rollwhere the work comes in contact with it.

2. An apparatus for shapinghollow sheet metal articles of polygonalcross-sectional outline, comprising "a plurality of rolls arranged toform thewalls of an aperture having said outline, the sides of'said'outline consisting, respectively, of elementsof said rolls, meanssupporting the peripheral surfaces of'sa'idrolls to hold them insaidrela tionship but enabling the 'rolls to rotate 'member havingajplurality of recesses in the wall of said aperture, rolls positionedin said recesses and supported bythe walls of said recesses, thesurfaces of said rolls constituting work shaping surfaces of said die,and means cooperating with said member to support the rolls in theiroperative positions.

4. An apparatus for shaping hollow sheet metal articles, comprising amiddle die plate having a hole therethrough, said hole having aplurality of recesses formed in the wall thereof, rolls fpositioned insaid recesses and arranged to rm the walls of an aperture of polygonaloutline, top and bottom plates cooperating with said middle plate tohold said rolls in their operative positions, said rolls being supportedby the engagement of their peripheral surfaces with the walls of saidrecesses, and a punch for forcing the work through said aperture.

WILLIAM WARREN SOMERSALL.

